DER X1 ALG series

DER X1 ALG series
  • About safety window
  • Introduction
  • Spec.
  • Insurance
  • Certification
  • Test video
  • The origin of the safety window for machine tools 

     High speed machining with advanced technology causes an increasing risk of the ejection of the internal parts by accidents. Therefore, the German Machine Tool Builders' Association (VDW) began a series of researches regarding the design and dimensioning of guards in machine tools since 1997. The findings also lead to following safety standards for machine tools defined by the European Union.

     According to the statistics of accident, chuck in the lathe caused the most much casualties since it is the heaviest part (over 2.5kg) in the list of components might ejected. For milling machine, milling cutter is the most often ejected components therefore it less than 0.1kg usually.

    However it could not take it lightly, the impact energy of components ejected would be much more than its actual weight. To prevent accident happen the safety window of machine tools has to be assessed by exactly and professionally.

  • Aging of PC vision window

    Safety window ageing
    The polycarbonate had already been proved that it is the most suitable material for safety windows for machine tools due to the high impact resistance. But the researches also showed that single layer of PC used in the machine window will be ageing under the influence of the metalworking fluids, cooling lubricants and cleaning solvent etc. in the machining process.
    The situation might be a potential risk for machine tools operators, since the safety window used to be main protection for operators from ejected objects.

    Impact resistance of safety window made by polycarbonate would reduce to 60% after using 2 years and even has a significant reduction about 80% after using for approximately 7 years under working environment. Therefore the operators will be at high risk of injury caused by internals ejected with high impact energy from the working zone. The German Machine Tool Bullders’ Association (VDW) also takes the PC vision window as consumptive materials and should renew regularly to keep operators safe.

  • Safety regulations defined by EU 

    Evolution of safety window

    The machine tool is flourish nowaday to make the process quicker the operating speed had been elevate a lot. However when unexpected accidents happen either cutting debris, tool breakage, loose jaws or working pieces pop, higher speeds mean higher impact energy of the ejected parts will make and put the machine operator exposed to extremely dangerous working conditions even cause life-threatening. 

    Therefore, the EU has already defined the relevant safety regulations in machine tools to make sure that machine operators were properly protected and declare that all the products in the EU market have to conform to the inspection standard of this safety regulation. 

  • Upgrade your machine window right away!

    machine tool
    Derstrong can provide high quality safety window which comply with EN ISO 23125 and EN ISO 16090-1 (EN 12417) by integrating both advantages of glass and polycarbonate to achieve irreplaceable safety window for machine tools.

    We have confidence to create added value and enhance the visibility of your machine tools, and then become the noticeable spotlight in the industry. Derstrong Enterprise Co., Ltd. aim to provide the total solution rather than sell the safety window only.
ALG series is an invented safety glass professionally for anti-fogging

  • Insulating layer with chamber inside of DER X1 ALG series is especially filled up with inert gas to prevent condensation issue due to humidity resulting from temperature difference between inside and outside the machine tools during processing.
  • DER X1 ALG series have the capabilities of withstanding splashed chips, scratching and cutting fluids & coolant lubricant without sacrificing your vision.
  • DER X1 ALG series could resist high energy impact and prevent to hurt operators by the shatterproof and anti-spalling design.

Key features 

  • Boundary laminated polycarbonate and glass
  • Insulating layer is composed of AI alloy and gas
  • Great impact resistance
  • Shatterproof and anti-spalling design
  • Safety shield for the operator during processing
  • Controlling the risk form ejected parts


  • No degradation after exposure to metalworking fluids
  • No condensation due to humidity and no blurred
  • Dual waterproof sealing design along the outer edges
  • Customization and curving type are both available
  • Complete traceability system each product has own ID number.
  • Durable, high quality and reliability.


Safety window ALG series


  • Small and large CNC lathe, milling machine
  • Grinding machine and machining centers
  • Other metalworking equipments

CE conformity

  • Verified by TÜV Rheinland
  • EN ISO 23125 & EN ISO 16090-1(EN 12417 before)
  • Safenet EC Examination Certificate


DER X1 ALG series impact energy contrast table with protect level of EN ISO 23125 & EN 12415
(For small lathe and machining center)

Product Types Thickness (mm) Tolerance±5% Resistance Class EN ISO 23125 Work holding device diameter (mm)  Perpheral    speed   (m/sec)  Projectile    dimensions   (mm)  Projectile   mass(kg) Impact speed (m/sec) Impact Energy (Joule)
DER 13.5 ALG 13.5 A1   130 25 30X19 0.625 32.89 338
DER 15.0 ALG 15.0 A2   130 40 30X19 0.625 50 781.3
DER 16.5 ALG 16.5 A2   130 40 30X19 0.625 51.02 813.14
DER 20.0 ALG 20.0 A3   130 63 30X19 0.625 80.65 2032.6
DER 15.0 ALG 15.0 B1 130 260 40 40x25 1.25 51.02 1628.2
DER 16.5 ALG 16.5 B1 130 260 40 40X25 1.25 51.02 1628.2
DER 18.5 ALG 18.5 B2 130 260 50 40X25 1.25 65.79 2707.4
DER 22.5 ALG 22.5 B3 130 260 63 40X25 1.25 80.65 4068.5
DER 20.0 ALG 20.0 C1 260 500 40 50X30 2.5 50.51 3189.1
DER 22.5 ALG 22.5 C2 260 500 50 50X30 2.5 64.1 5136
DER 25.5 ALG 25.5 C3 260 500 63 50X30 2.5 80.65 8130.5

DER X1 ALG series impact energy contrast table with protect level of EN ISO 16090-1 (EN 12417)
(For milling machining and machining center)

Product Types Thickness (mm) Tolerance±5% Impact speed m/sec Impact energy (Joule) Projectile dimension (mm) Projectile mass (kg)
DER 13.5 ALG 13.5 78.1 305    20x41          0.1Kg     
DER 15.0 ALG 15.0 94.3 444.6
DER 16.5 ALG 16.5 104.2 542.9
DER 18.5 ALG 18.5 125 781.3
DER 20.0 ALG 20.0 138.9 964.7
DER 22.5 ALG 22.5 156.3 1221.5

DER X1 ALG series impact energy contrast table with protect level of EN ISO 23125 & EN 12478
CNC large lathe and machining center etc...)

Products Types Thickness (mm) Tolerance±5% Impact speed m/sec Impact energy (Joule) Projectile dimension ( mm ) Projectile mass (kg)
DER 18.5 ALG 18.5 49.02 3003.7    50x30        2.5    
DER 20.0 ALG 20.0 55.56 3858.6
DER 22.5 ALG 22.5 62.5 4882.8
All products conformity with CE certification subject to Directive 2006/42/EC 

  • EN ISO 23125 for CNC Lathe certificate
  • EN ISO 16090-1 for machining center ( EN 12417 before)
  • Verified by TÜV Rheinland


Impact resistance test video

  • All series of safety windows are CE certificated.
  • Customizable safety window for machine tool.
  • All series products passed impact test.